This invention relates to a system for controlling apparatus used for peeling and coiling a continuous strip of metal cut from a rotating billet, and more particularly, to a system for tensioning and examining the strip during operation of the machine.
Machines have been built to manufacture thin metal strips by continuously feeding or moving a cutting tool at a specific rate into the peripheral surface of a rotating metal billet so as to cut and peel a continuous metal strip therefrom. The cylindrical billets used for strip peeling are formed through the compression of metal powders typically comprised of high temperature alloys such as stainless steel alloys.
Existing machines have utilized a tension producing coiling assembly as part of the peeling process. The coiling assembly can include a motor driven rotatable spindle with a wrapping mechanism to assist in the threading of the peel onto the coiler. The rotating spindle pulls and coils the metal strip as it is peeled from the billet.
Control systems have been developed whereby the surface speed of the billet, the speed of the peeled strip and the rate of advancement of the cutting tool into the surface of the billet can be adjusted to accurately control the thickness of the strip. U.S. Pat. No. 4,274,315 discloses such a control system wherein sensors are used to monitor the thickness of the strip and correct for unwanted variations thereof.
Monitoring and control of strip tension is of particular importance in applications where the strip tension varies during the peeling operation. Such variations can arise due to an abrupt change in the metallurgy of the billet, because of any change in the rate of cooling at the cutting edge or due to a buildup of debris on the tool surface. A control circuit can be used to gather and process information from the various system components to maximize operating speed of the machine.